WSJT-X/lib/jt65sim.f90

131 lines
4.1 KiB
Fortran
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program jt65sim
! Generate simulated data for testing of WSJT-X
use wavhdr
use packjt
parameter (NTMAX=54)
parameter (NMAX=NTMAX*12000)
type(hdr) h
integer*2 iwave(NMAX) !Generated waveform
integer*4 itone(126) !Channel symbols (values 0-65)
integer dgen(12),sent(63)
real*4 dat(NMAX)
real*8 f0,dt,twopi,phi,dphi,baud,fsample,freq,sps
character msg*22,arg*8,fname*11,csubmode*1
integer nprc(126)
data nprc/1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1,0,0, &
0,1,0,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,1,1, &
0,1,1,0,1,1,1,1,0,0,0,1,1,0,1,0,1,0,1,1, &
0,0,1,1,0,1,0,1,0,1,0,0,1,0,0,0,0,0,0,1, &
1,0,0,0,0,0,0,0,1,1,0,1,0,0,1,0,1,1,0,1, &
0,1,0,1,0,0,1,1,0,0,1,0,0,1,0,0,0,0,1,1, &
1,1,1,1,1,1/
nargs=iargc()
if(nargs.ne.5) then
print*,'Usage: jt65sim mode nRay nsigs SNR nfiles'
print*,'Example: jt65sim B 0 10 -24 1'
print*,'Enter SNR = 0 to generate a range of SNRs.'
go to 999
endif
csubmode='A'
call getarg(1,csubmode)
mode65=1
if(csubmode.eq.'B') mode65=2
if(csubmode.eq.'C') mode65=4
call getarg(2,arg)
read(arg,*) nRay !1 ==> Rayleigh fading
call getarg(3,arg)
read(arg,*) nsigs !Number of signals in each file
call getarg(4,arg)
read(arg,*) snrdb !S/N in dB (2500 hz reference BW)
call getarg(5,arg)
read(arg,*) nfiles !Number of files
rmsdb=25.
rms=10.0**(0.05*rmsdb)
fsample=12000.d0 !Sample rate (Hz)
dt=1.d0/fsample !Sample interval (s)
twopi=8.d0*atan(1.d0)
npts=54*12000
baud=11025.d0/4096.d0
sps=12000.d0/baud !Samples per symbol, at fsample=12000 Hz
nsym=126
h=default_header(12000,npts)
do ifile=1,nfiles !Loop over all files
write(fname,1002) ifile !Output filename
1002 format('000000_',i4.4)
open(10,file=fname//'.wav',access='stream',status='unknown')
if(snrdb.lt.90) then
do i=1,npts
dat(i)=gran() !Generate AWGN
enddo
else
dat(1:npts)=0.
endif
dfsig=2000.0/nsigs
do isig=1,nsigs
if(mod(nsigs,2).eq.0) f0=1500.0 + dfsig*(isig-0.5-nsigs/2)
if(mod(nsigs,2).eq.1) f0=1500.0 + dfsig*(isig-(nsigs+1)/2)
nsnr=nint(snrdb)
if(snrdb.eq.0.0) nsnr=-19 - isig
if(csubmode.eq.'B' .and. snrdb.eq.0.0) nsnr=-21 - isig
if(csubmode.eq.'C' .and. snrdb.eq.0.0) nsnr=-21 - isig
write(msg,1010) nsnr
1010 format('K1ABC W9XYZ ',i3.2)
call packmsg(msg,dgen,itype) !Pack message into 12 six-bit bytes
call rs_encode(dgen,sent) !RS encode
call interleave63(sent,1) !Interleave channel symbols
call graycode65(sent,63,1) !Apply Gray code
k=0
do j=1,nsym
if(nprc(j).eq.0) then
k=k+1
itone(j)=sent(k)+2
else
itone(j)=0
endif
enddo
sig=10.0**(0.05*nsnr)
! sig=1.122*sig
if(nsnr.gt.90.0) sig=1.0
write(*,1020) ifile,isig,f0,csubmode,nsnr,sig,msg
1020 format(i4,i4,f10.3,1x,a1,i5,f8.4,2x,a22)
phi=0.d0
dphi=0.d0
k=12000 !Start audio at t = 1.0 s
isym0=-99
do i=1,npts
isym=nint(i/sps)+1
if(isym.gt.nsym) exit
if(isym.ne.isym0) then
freq=f0 + itone(isym)*baud*mode65
dphi=twopi*freq*dt
isym0=isym
endif
phi=phi + dphi
if(phi.gt.twopi) phi=phi-twopi
xphi=phi
k=k+1
dat(k)=dat(k) + sig*sin(xphi)
enddo
enddo
fac=32767.0/nsigs
if(snrdb.ge.90.0) iwave(1:npts)=nint(fac*dat(1:npts))
if(snrdb.lt.90.0) iwave(1:npts)=nint(rms*dat(1:npts))
write(10) h,iwave(1:npts)
close(10)
enddo
999 end program jt65sim